The Diagnostic Laboratory of the Duke Comprehensive Sickle Cell Center has been organized to provide accurate phenotypic and genotypic data on patients being studied at the Center. Because of the considerable heterogeneity in the clinical course of sickle cell patients and among individual cells in the blood of patients with sickle cell disease, clinical and basic laboratory research requires an understanding of the patients or blood samples being examined. The laboratory also has the responsibility for developing protocols to effectively communicate this information to the investigators using the information and to develop approaches that will ultimately lead to improved algorithms for care for patients with sickling disorders.